Adjustable Compression Staple and Method for Stapling With Adjustable Compression

ABSTRACT

A substantially U-shaped staple has a bridge, legs, and an internally disposed compression device with a bias portion having a compression surface movably disposed between the legs and a compression resistor connected to the bridge and to the compression surface and is formed to resist movement of the compression surface towards the bridge with a force.

CROSS-REFERENCE TO RELATED APPLICATION

This application is:

-   -   a divisional of U.S. patent application Ser. No. 13/222,758        filed on Aug. 31, 2011; and    -   a divisional of U.S. patent application Ser. No. 11/971,998        filed on Jan. 10, 2008 (which application claims the benefit        under 35 U.S.C. §119(e) of U.S. Provisional Application No.        60/880,146 filed Jan. 12, 2007),        the complete disclosures of which are hereby incorporated by        reference herein in their entireties.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

FIELD OF THE INVENTION

The present invention lies in the field of staple fastening, inparticular, staples and instruments capable of applying a single or aplurality of staples to a material and processes therefor. Moreparticularly, the present invention relates to a staple capable ofplacing a load-bearing force against the material being stapled andimprovements in processes for stapling material. The device can be used,particularly, in the medical field for stapling tissue during surgicalprocedures, whether open, endoscopic, or laparoscopic.

BACKGROUND OF THE INVENTION

Conventional staples are, typically, U-shaped and require a staplecartridge and anvil to fasten the staple onto a material. The U-shape ofthe staple can be considered relatively square-cornered because of thesharp angle at which the legs extend from the bridge. On activation of astapling device, the staple legs are advanced forward so that theypenetrate a material on both sides of a slit or opening. As a stapleformer is advanced further, the legs of the staple bend around the anvilcausing the tips of the legs to advance along an arcuate path towardeach other so that the staple ultimately assumes a generally rectangularshape, thereby compressing the material that has been trapped betweenthe staple legs, which is tissue in surgical applications. Thiscompression of the material is the mechanism by which a closure iseffected. Depending on the length of the incision or opening, a seriesof staples will be delivered along its length, which can ensure a bloodtight closure in surgical procedures.

Because the staple has two legs that pierce the material, they are wellsuited for fastening two or more layers of material together when usedwith the opposing anvil. Whether used in an office or during a surgicalprocedure, most staples 1 have similar shapes—a bridge 2 connecting tworelatively parallel legs 4, which legs are disposed approximatelyorthogonal to the bridge 2, which, depending on the material of thestaple, results in a square-cornered U-shape. In surgical staplingdevices, it is beneficial to start the legs 4 in a slight outwardorientation to assist retention of the staples within the cartridge. Thestaple illustrated in FIG. 1 is representative of conventional surgicalstaples. Such staples are compressed against an anvil to bend the tipsof the legs 4 inward. For purposes sufficient in surgery, the finalstapled configuration has a stapling range from a “least” acceptableorientation to a “greatest” acceptable orientation. The “least”acceptable staple range is a position where the tangent defined by thetip of each leg 4 is at a negative angle to a line parallel to thebridge 2 and touching the lower portions of both legs 4. The “greatest”acceptable staple range is a position where the legs 4 are bent into ashape similar to the letter “B.”

The staple 1 of FIG. 1 is shown in an orientation where the tips of thelegs 4 are bent slightly by an anvil on the way towards a final stapledform. (This slightly bent orientation is also present with respect tothe staples illustrated hereafter.) The legs 4 of such slightly bentstaples have three different portions:

-   -   a connecting portion 6 (at which the legs 4 are connected to the        bridge 2);    -   an intermediate portion 8 (at which the staple is bent; of        course it is also possible for the connection portion 6 to be        bent for various fastening purposes); and    -   a piercing portion 10 (for projecting through the material to be        fastened; this portion, too, is bent when fastening).        Many stapling devices exist to deploy such staples. Some        surgical stapling instruments are described in U.S. Pat. No.        5,465,895 to Knodel et al., and U.S. Pat. Nos. 6,644,532 and        6,250,532 to Green et al. When the staple 1 is bent for        fastening, the polygon formed by the interior sides of the bent        staple 1 defines an envelope or a central region 14. The        material to be fastened by the staple 1 resides in and is        compressed within the central region 14 when stapling occurs.        When the final staple orientation is B-shaped, there can be two        regions in which the tissue is held and compressed.

One common feature associated with conventional staples is that there isno controllable way of adjusting the compressive force that is appliedby the staple to the material being stapled. While items such as paperand cardboard can withstand a wide range of stapler compressive forcewithout breaking or puncturing, living tissue, such as the tissue to befastened in a surgical procedure, has a limited range of compressiveforce and cannot withstand force greater than a upper limit within thatrange without causing tissue damage. In fact, the range of optimalstapling force for a given surgical stapling procedure is relativelysmall and varies substantially with the type of tissue being stapled.

While it may be true that the distance between the bending point of thelegs and the bridge (see, e.g., span 12 in FIG. 1) can be increased toimpart less force on material within the staple, this characteristicdoes not apply when living tissue having varying degrees of hardness,composition, and flexibility is the material being stapled. Even if thestaple leg bending distance 12 is increased, if more or less or harderor softer tissue than expected is actually captured within the staple,the force applied to the captured tissue will not be controlled and willnot be optimal for that tissue.

When one, two, or more layers of tissue are being stapled, it isdesirable for the tissue to be at a desired compressive state so that adesirous medical change can occur, but not to be at an undesiredcompressive state sufficient to cause tissue necrosis. Because there isno way to precisely control the tissue that is being placed within thestaple, it is not possible to ensure that the tissue is stapled withinan optimal tissue compression range, referred to as an OTC range.Therefore, ruling out of tissue necrosis is difficult or not possible.Further, tissue presented within one staple may not be the same tissuethat is presented within an adjacent staple or is within another staplethat is fired during the same stapling procedure. Thus, while one or afew of a set of staples could actually fasten within the OTC range, itis quite possible for many other staples in the same stapling procedureto fasten outside the OTC range.

What is needed, therefore, is an improved staple and improved methods ofstapling that allow automatic control of the staple compression forceimparted upon the material being stapled so that compression of thematerial remains within a desired OTC range. While prior art surgicalstapling instruments have utility, and may be successfully employed inmany medical procedures, it is desirable to enhance their operation withthe ability to deliver a staple that can automatically tailor thecompression force delivered to the tissue without external mechanics oroperations.

BRIEF SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide an adjustablecompression staple and methods for stapling with adjustable compressionthat overcome the hereinafore-mentioned disadvantages of theheretofore-known devices and methods of this general type and thatautomatically tailors the compression force delivered to the tissue.

When tissue is stapled, liquid is forced out of the tissue. The OTCrange of the tissue is a compression range in which liquid is removedfrom the tissue (i.e., desiccates the tissue) without damaging ornecrosing the tissue. As the liquid from the tissue exits the tissue dueto compression exerted upon the tissue by the staple, however, thecompressive force that is being imposed upon the tissue naturallyreduces—because less mass is between the opposing staple portions. Insome instances, this reduction can allow the imparted tissue compressionto exit the OTC range. Staples according to the present invention eachhave a self-adjusting, pre-tensioned compression device that keepscompression force on the interposed tissue within the OTC compressionrange even after being desiccated.

The prior art staple of FIG. 1 has a stapling range that is illustratedin FIG. 17. For purposes sufficient in surgery, the final stapledconfiguration of the OTC staples of the present invention has a staplingrange that is illustrated, for example, in FIGS. 18 to 20. A “least”acceptable staple range is a position where the tangent T defined by thetip of each leg 4 is at a negative angle α to a line L parallel to thebridge 2. This orientation is illustrated with the left half of thestaple in FIG. 17 merely for reasons of clarity. See also FIGS. 18 to20. A “greatest” acceptable staple range is a position where the legs 4are bent 180 degrees into a shape similar to the letter “B” (see theexemplary orientation illustrated in the right-half of FIG. 17) but, incomparison to the prior art staple range of FIG. 17, as described belowin detail, the tips of the legs 4 of the staples according to theinvention reach only up to a compressing portion and not further thanthis compressing portion as shown in FIG. 20, for example. In such anorientation, the stapled tips of the legs do not interfere with the OTCdevice present in the staples according to the invention.

The OTC devices for staples according to the invention take many forms.The OTC device can be integral with the legs of the staple and projectinto a central area or can be attached to the staple to project into thecentral area. The OTC device can be sinusoidal in shape with acompressing portion at the end of the OTC device or can be have multiplecycles of bends between the bridge of the staple with the compressingportion at the end of the OTC device. The bending portion can be singleor double, the double bends being in cycle, out of cycle,mirror-symmetrical, to name a few. The bends can be double-sinusoidal asshown in FIGS. 8, 9, and 11 The OTC device can be contained entirelybetween the two legs of the staple or can encircle one or both of thelegs and, thereby, use the legs as a guide, for example, a slidingguide. The leg encirclement by the OTC device can be single or multiple.Travel of the OTC device can be limited, for example, by a star washer.The OTC device can be a compression spring(s) and a plate(s), with theplate encircling the legs and sliding thereon. The OTC device can be acompressible material secured on the legs. This material can be in theshape of a plate or a pillow.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a substantially U-shaped staple having abridge, legs, and an internally disposed compression device having abias portion with a compression surface movably disposed between thelegs and a compression resistor connected to the bridge and to thecompression surface and is formed to resist movement of the compressionsurface towards the bridge with a force.

In accordance with another feature of the invention, the bridge issubstantially rod-shaped with ends and the base end of each of the legsis integral with a respective one of the ends.

In accordance with a further feature of the invention, the bridge andlegs define a bridge-leg plane and the legs extend from the bridge at anangle of between 80 and 100 degrees in the bridge-leg plane.

In accordance with an additional feature of the invention, thecompression surface defines two orifices and each of the legs extendsthrough one of the two orifices.

In accordance with yet another feature of the invention, the compressionresistor defines at least one orifice pair, the compression surfacedefines two orifices, and each of the legs extends through one of thetwo orifices and one of the at least one orifice pair.

In accordance with yet a further feature of the invention, thecompression resistor defines a plurality of orifice pairs, thecompression surface defines two orifices, and each of the legs extendsthrough one of the two orifices and one of each of the orifice pairs.

In accordance with yet an added feature of the invention, the bridge andthe legs define a compression axis and the compression surface ismovably disposed between the legs along the compression axis.

In accordance with yet an additional feature of the invention, thecompression device is connected to the bridge.

In accordance with again another feature of the invention, thecompression resistor connects the bridge to the compression surface.

In accordance with again a further feature of the invention, the bridge,the legs, the compression resistor, and the compression surface areintegral.

In accordance with again an added feature of the invention, thecompression resistor is at least partly disposed between the legs.

In accordance with again an additional feature of the invention, thecompression resistor is disposed between the bridge and the compressionsurface.

In accordance with still another feature of the invention, the force isa pre-defined opposing force.

In accordance with still a further feature of the invention, the forceis a substantially constant force.

In accordance with still an added feature of the invention, the force isa linearly increasing force.

In accordance with still an additional feature of the invention, thecompression resistor has an anti-compressive spring constant imparting asubstantially constant anti-compressive force over a pre-definedcompression range.

In accordance with another feature of the invention, the staple and thecompression device are of a biocompatible material.

In accordance with a further feature of the invention, the compressionsurface and the legs define a central compression region in which is tobe disposed a material to be compressed between the compression surfaceand stapling points when distal ends of the staple legs are deformed.When the distal ends are deformed in a staple closing direction into thecentral compression region, the bias portion resists movement of thecompression surface in the staple closing direction with a pre-defined,substantially constant force.

In accordance with an added feature of the invention, the compressionsurface and the bias portion are shaped to impart a pre-defined,substantially constant bias force upon material disposed between thecompression surface and stapling points when the stapling points aredeformed.

In accordance with a concomitant feature of the invention, when staplingpoints are deformed toward one another, material disposed between thecompression surface and the stapling points is compressed between thestapling points and the compression surface. The compression resistormaintains a substantially constant compressive force on the materialwithin a pre-defined range independent of a degree of compressionbetween stapling points and the compression surface.

Although the invention is illustrated and described herein as embodiedin an adjustable compression staple and method for stapling withadjustable compression, it is, nevertheless, not intended to be limitedto the details shown because various modifications and structuralchanges may be made therein without departing from the spirit of theinvention and within the scope and range of equivalents of the claims.Additionally, well-known elements of exemplary embodiments of theinvention will not be described in detail or will be omitted so as notto obscure the relevant details of the invention.

Other features that are considered as characteristic for the inventionare set forth in the appended claims. As required, detailed embodimentsof the present invention are disclosed herein; however, it is to beunderstood that the disclosed embodiments are merely exemplary of theinvention, which can be embodied in various forms. Therefore, specificstructural and functional details disclosed herein are not to beinterpreted as limiting, but merely as a basis for the claims and as arepresentative basis for teaching one of ordinary skill in the art tovariously employ the present invention in virtually any appropriatelydetailed structure. Further, the terms and phrases used herein are notintended to be limiting; but rather, to provide an understandabledescription of the invention. While the specification concludes withclaims defining the features of the invention that are regarded asnovel, it is believed that the invention will be better understood froma consideration of the following description in conjunction with thedrawing figures. The figures of the drawings are not drawn to scale.

Before the present invention is disclosed and described, it is to beunderstood that the terminology used herein is for the purpose ofdescribing particular embodiments only and is not intended to belimiting. The terms “a” or “an”, as used herein, are defined as one ormore than one. The term “plurality,” as used herein, is defined as twoor more than two. The term “another,” as used herein, is defined as atleast a second or more. The terms “including” and/or “having,” as usedherein, are defined as comprising (i.e., open language). The term“coupled,” as used herein, is defined as connected, although notnecessarily directly, and not necessarily mechanically.

As used herein, the term “about” or “approximately” applies to allnumeric values, whether or not explicitly indicated. These termsgenerally refer to a range of numbers that one of skill in the art wouldconsider equivalent to the recited values (i.e., having the samefunction or result). In many instances these terms may include numbersthat are rounded to the nearest significant figure.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the embodiments of the present invention will be apparentfrom the following detailed description of the preferred embodimentsthereof, which description should be considered in conjunction with theaccompanying drawings in which:

FIG. 1 is a perspective view from above a side of an exemplary prior artsurgical staple;

FIG. 2 is a perspective view from above a side of a first exemplaryembodiment of an OTC staple according to the invention;

FIG. 3 is a perspective view from above a side of a second exemplaryembodiment of an OTC staple according to the invention;

FIG. 4 is a perspective view from above a side of a third exemplaryembodiment of an OTC staple according to the invention;

FIG. 5 is a perspective view from above a side of a fourth exemplaryembodiment of an OTC staple according to the invention;

FIG. 6 is a perspective view from above a side of a fifth exemplaryembodiment of an OTC staple according to the invention;

FIG. 7 is a perspective view from above a side of a sixth exemplaryembodiment of an OTC staple according to the invention;

FIG. 8 is a perspective view from above a side of a seventh exemplaryembodiment of an OTC staple according to the invention;

FIG. 9 is a perspective view from above a side of an eighth exemplaryembodiment of an OTC staple according to the invention;

FIG. 10 is a perspective view from above a side of a ninth exemplaryembodiment of an OTC staple according to the invention;

FIG. 11 is a perspective view from above a side of a tenth exemplaryembodiment of an OTC staple according to the invention;

FIG. 11A is a fragmentary, enlarged perspective view from below a sideof the OTC staple of FIG. 11;

FIG. 12 is a perspective view from above a side of an eleventh exemplaryembodiment of an OTC staple according to the invention;

FIG. 13 is a perspective view from above a side of a twelfth exemplaryembodiment of an OTC staple according to the invention;

FIG. 14 is a perspective view from above a side of a thirteenthexemplary embodiment of an OTC staple according to the invention;

FIG. 15 is a perspective view from above a side of a fourteenthexemplary embodiment of an OTC staple according to the invention;

FIG. 16 is a perspective view from above a side of a fifteenth exemplaryembodiment of an OTC staple according to the invention;

FIG. 17 is a side elevational view of the prior art surgical staple ofFIG. 1 with the staple tips illustrating an exemplary range of stapling;

FIG. 18 is a side elevational view of the staple of FIG. 6 with thestaple tips in a first intermediate position of an exemplary staplingrange;

FIG. 19 is a side elevational view of the staple of FIG. 6 with thestaple tips in a second intermediate position of an exemplary staplingrange; and

FIG. 20 is a side elevational view of the staple of FIG. 6 with thestaple tips in a third intermediate position of an exemplary staplingrange.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Herein various embodiment of the present invention are described. Inmany of the different embodiments, features are similar. Therefore, toavoid redundancy, repetitive description of these similar features maynot be made in some circumstances. It shall be understood, however, thatdescription of a first-appearing feature applies to the later describedsimilar feature and each respective description, therefore, is to beincorporated therein without such repetition.

Referring now to the figures of the drawings in detail and first,particularly to FIG. 2 thereof, there is shown a first exemplaryembodiment of an automatic optimal tissue compression (OTC) staple 20according to the invention. In this first embodiment, the bridge 21 hasa center bridge portion 22 and an extension 23 that substantiallyincreases the overall length of the bridge 21—as compared to the bridge2 of the staple 1 of FIG. 1. As the upper bridge portion 22 transitionsinto the extension 23, it curves into and within the central region 24of the staple 20. This extension 23 can be in any shape or of anymaterial so long as it delivers a pre-set compressive force to thetissue at a compressing portion 25, and as long as it allows forabsorption (within the area between the compressing portion 25 and theupper bridge portion 22) of forces greater than this pre-set force.Therefore, the shape can be trapezoidal, triangular, sinusoidal, or anyother configuration. An exemplary embodiment of relatively sinusoidalcurves is shown in FIG. 2. These curves traverse two periods in theillustrated embodiment, however, the number of wave periods can bevaried (smaller or larger). The extension 23 has two mirror-symmetricalportions each starting from the upper bridge portion 22 and ending atrespective ends of the compressing portion 25. Further, it is noted thatneither the extension 23 nor the compressing portion 25 directlycontacts the legs 26 in this exemplary configuration.

In the embodiment of FIG. 2, the extension 26 and the compressingportion 29 are integral with the upper bridge portion 22 and a base end27 of the legs 26. The legs 26 are shown as relatively circular incross-section. The bridge 21 and all of the compressing components 22,23, 25 can also be circular in cross-section. Alternatively, as shown inFIG. 2, any portion of the extension 23 and/or the compressing portion25 can have different cross-sectional shapes, such as ovular,rectangular, or polygonal. In the embodiment shown, the cross-section ofthe extension 23 after the first curve away from the upper bridgeportion 22 is shaped in a “racetrack” form (two relatively straightsides with two curved ends connecting each end of the sides). The upperbridge portion 22 can also have a different cross-sectional shape. Theextension 23 and compressing portion 25 are, in this embodiment, even incross-sectional area. Different portions of these parts can, however,have varying cross-sectional areas (i.e., varying thicknesses) asdesired.

When the upper bridge 22, the extension 23, and the compressing portion25 are shaped to deliver the pre-set compressive force to the tissue ina substantially longitudinal direction 28 of an unbent section of theleg portions 26 and to absorb forces greater than this pre-set force,the overall effect is to create an OTC device having a given springcoefficient. In other words, the OTC device maintains the presetcompressive force within the stapled area even after tissue changesstates, such as expanding due to swelling and/or contracting duringdesiccation. Variation of the cross-section of any portion of the upperbridge 22, the extension 23, and the compressing portion 25 will allowfor different OTC spring coefficients and, therefore, allows foradjustment of the compressive and reactive force constants of the OTCdevice within the staple 20. Variation of the material making up all ofthe staple 20 or any of its portions also permits adjustment of the OTCforce.

FIG. 3 illustrates a second exemplary embodiment of the OTC staple 30according to the invention. In this variation, as compared to theembodiment of FIG. 2, the OTC portion is not integral with the bridge 31and the legs 32. Instead, the OTC device 33 is separate therefrom and isconnected to these staple portions. Specifically, the OTC device 33 hasa compressing portion 34 that directly contacts the tissue beingcompressed and an extension 36 for providing the load-bearing force whentissue is compressed within the central region 37 of the staple 30. TheOTC device 33 also has a connecting portion 35 for attaching the OTCdevice 33 to the bridge 31. The extension 36 connects the upper andlower portions 34, 35 of the OTC device 33. The extension 33 and thecompressing portion 34 are, in this embodiment, different incross-sectional area. Here, the cross-sectional area of the compressingportion 34 is wider than the extension 36. Any portions of the extension33 or the compressing portion 34 can be varied to have same or varyingcross-sectional areas (i.e., varying thicknesses).

Connection of the OTC device 33 to the staple, for example, at thebridge 31, can occur by any fastening measure. One exemplary connectionmethod is spot welding, which is indicated in FIG. 3 by referencenumeral 38. Other exemplary methods of attaching suitable materialstogether include soldering and brazing. The type or types of material ofthe staple portions 31, 32 and the OTC device 33 will direct apreferable attachment method. In the case of attaching two materialstogether that are not suited to be welded, soldered or brazed, otherattachment methods can be used such as crimping and adhesive bonding.Features can be added to one or both of the two components to facilitatethe crimp or bond. These features could be configured to have thecomponents snap together. In the case of dissimilar materials, forexample, if the staple material is stainless steel and the OTC device 33is of nickel titanium alloy, then preferred attachment measures includecrimping, adhesive bonding, or snapping.

In this second embodiment, the OTC device 33 behaves similar to the OTCportions of the embodiment of FIG. 2 and can be shaped with the samevariations of cross-section and other spatial characteristics and can beformed with the same variations in material composition. Variation ofany attribute of the OTC device 33 allows for adjustment of thecompressive and reactive force constants thereof on the compressedtissue. The extension 36 can be any shape or material so long as itdelivers a pre-set compressive force to the tissue at the compressingportion 34 and as long as it allows for absorption of forces greaterthan this pre-set force. An exemplary embodiment selected for thisexemplary OTC device 33 is a relatively sinusoidal set of curvestraversing less than two periods. The extension 36 has twominor-symmetrical portions each starting from the bridge 31 and endingat respective ends of the compressing portion 34. In this exemplaryembodiment, neither the extension 36 nor the compressing portion 34directly contacts the legs 32. Most of the cross-section of the OTCdevice 33 has a racetrack form. Like the embodiment of FIG. 2, thecross-section can be varied in any desired way to deliver the pre-setcompressive force to the tissue and to absorb forces greater than thispre-set force.

FIG. 4 illustrates a third exemplary embodiment of the OTC staple 40according to the invention. In this variation, as compared to theembodiments of FIGS. 2 and 3, the OTC portion 43 is not symmetrical withrespect to the bridge 41 or the legs 42. Also, like the embodiment ofFIG. 3, the OTC portion is not integral with either the bridge 41 or thelegs 42. The OTC device 43 is a separate part from the bridge 41 and thelegs 42 and is fixedly connected to the bridge 41 at a connectionlocation (for example, with a spot weld 48; other fixation/connectionprocesses can be used). In particular, a connecting portion 45 of theOTC device 43 fixedly secures the OTC device 43 to the bridge 41. Anextension 46 of the OTC device 43 provides the load-bearing force whentissue is compressed within the central region 47 of the staple 40 and acompressing portion 44 directly contacts the tissue being compressed.

Notably different from the embodiments of FIGS. 2 and 3 is thecompressing portion 44. Here, the width of the compressing portion 44(defined along the line between the two legs 42 of the staple 40) isgreater than the separation distance of the two legs 42. The compressingportion 44 is provided with orifices 49 having a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thestaple legs 42 but slightly larger. The legs 42 pass through andslidably rest within these orifices 49. In such a configuration,movement of the OTC device 43 out of the bridge-legs plane issubstantially prevented. Because the orifices 49 are shaped to beslightly larger than the cross-section of the legs 42, the extension 46acts as a compression spring in the bridge-legs plane as the compressingportion 44 moves up and down along the upper portion of the legs 42 (upbeing defined as the direction towards the bridge 41 from the piercingtips of the legs 42). Thus, the OTC device 43 of the third embodimentbehaves different from the OTC devices of FIGS. 2 and 3 because of theform-locking and sliding connection between the connecting portion 44and the legs 42. A form-locking connection is one that connects twoelements together due to the shape of the elements themselves, asopposed to a force-locking connection, which locks the elements togetherby force external to the elements.

Like the previous embodiments, the OTC device 43 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. The extension 46 andcompressing portion 44 are, in this embodiment, different incross-sectional area. Here, the cross-sectional area of the compressingportion 44 is wider than the extension 46. Any portions of the extension46 or the compressing portion 44 can be varied to have same or varyingcross-sectional areas (i.e., varying thicknesses). The extension 46 canbe any shape or material so long as it delivers the pre-set compressiveforce to the tissue at the compressing portion 44 and as long as itallows for absorption of forces greater than this pre-set force. Anexemplary embodiment selected for this OTC device 43 is a relativelysinusoidal curve traversing approximately one sinusoidal period.Virtually all of the cross-section of the OTC device 43 has a racetrackform, but can be changed as desired to other shapes (e.g., circular,ovular, polygonal, etc.). As described above, variation of any attributeof the OTC device 43 allows for adjustment of the compressive andreactive force constants thereof on the compressed tissue in the centralregion 47.

FIG. 5 illustrates a fourth exemplary embodiment of the OTC staple 50according to the invention. This variation has some of the features ofthe above embodiments. In this variant, like the embodiment of FIG. 2,the OTC portion is symmetrical with respect to the bridge 51 and thelegs 52 and the OTC device 53 is integral with the bridge 51. Like theembodiment of FIG. 4, the compressing portion 54 has a width greaterthan the separation distance of the two legs 52 and has ports 55 with ashape substantially corresponding to the cross-sectional shape of theupper portion of the legs 52, but slightly larger. The legs 52 passthrough these ports 55. In this configuration, movement of the OTCdevice 53 out of the bridge-legs plane is substantially prevented. Theextension 56 of the OTC device 53 traverses from the bridge 51 to thecompressing portion 54. Because the ports 55 are shaped to be slightlylarger than the cross-section of the legs 52, the extension 56 acts as acompression spring in the bridge-legs plane as the compressing portion54 moves up and down along the upper portion of the legs 52. It is theextension 56 that provides the load-bearing force when tissue iscompressed within the central region 57 of the staple 50. Because of theform-locking and sliding connection between the compressing portion 54and the legs 52, the OTC device 53 of the fourth embodiment behavessimilar to the OTC devices of FIG. 4.

Here, the OTC device 53 is integral with the legs 52, the bridge 51, andthe compressing portion 54. Because the two sides of the bridge 51 arenot integral, they can separate from one another when the staple 50 issubjected to a twisting force. If desired, to substantially prevent suchseparation, the central portions of the bridge 51 can be fixedlyconnected to one another at a connection location (for example, with aspot weld 58; other connection processes can be used as well).

Like the previous embodiments, the OTC device 53 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portions of theextension 56 or the compressing portion 54 can be varied to have thesame or varying cross-sectional areas (i.e., varying thicknesses). Theextension 56 and compressing portion 54 are, in this embodiment,different in cross-sectional areas. Here, the cross-sectional area ofthe upper majority of the extension 56 is narrower than the lowerportion of the extension 56 and the cross-section of the lower portionof the extension 56 gradually increases in width until it is equal tothe cross-section of the compressing portion 54.

The extension 56 can be any shape or material so long as it delivers thepre-set compressive force to the tissue at the compressing portion 54and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 53is a relatively sinusoidal curve traversing more than one sinusoidalperiod. Again, only for illustrative purposes, the cross-section of theOTC device 53 has a racetrack shape, but can be changed as desired toother shapes (e.g., circular, ovular, polygonal, etc.). As describedabove, variation of any attribute of the OTC device 53 allows foradjustment of the compressive and reactive force constants thereof onthe compressed tissue in the central region 57.

FIG. 6 illustrates a fifth exemplary embodiment of the OTC staple 60according to the invention. This variation has some of the features ofthe above embodiments. In this variant, like the embodiment of FIG. 3,the OTC portion is symmetrical with respect to the bridge 61 and thelegs 62 and the OTC device 63 is a separate part from the bridge 61 andlegs 62 of the staple 60. Like the embodiment of FIGS. 4 and 5, thecompressing portion 64 has a width greater than the separation distanceof the two legs 62 and has ports 65 with a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thelegs 62, but slightly larger. The legs 62 pass through these ports 65.In this configuration, movement of the OTC device 63 out of thebridge-legs plane is substantially prevented. The extension 66 of theOTC device 63 traverses from the bridge 61 to the compressing portion64. Because the ports 65 are shaped to be slightly larger than thecross-section of the legs 62, the extension 66 acts as a compressionspring in the bridge-legs plane as the compressing portion 64 moves upand down along the upper portion of the legs 62. It is the extension 66that provides the load-bearing force when tissue is compressed withinthe central region 67 of the staple 60. Because of the form-locking andsliding connection between the compressing portion 64 and the legs 62,the OTC device 63 of the fifth embodiment behaves similar to the OTCdevices of FIGS. 4 and 5.

Connection of the OTC device 63 to the staple 60, for example, at thebridge 61, can occur by any fastening measure. One exemplary connectionmethod is spot welding, which is indicated in FIG. 6 by referencenumeral 68. The type or types of material of the staple portions 61, 62and the OTC device 63 will direct a preferable attachment method. In thecase of attaching two materials together that are not suited to bewelded, soldered or brazed, other attachment methods can be used such ascrimping and adhesive bonding. Features can be added to one or both ofthe two components to facilitate the crimp or bond. These features couldbe configured to have the components snap together. In the case ofdissimilar materials, for example, if the staple material is stainlesssteel and the OTC device 63 is of nickel titanium alloy, then preferredattachment measures include crimping, adhesive bonding, or snapping.

Like the previous embodiments, the OTC device 63 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portions of theextension 66 or the compressing portion 64 can be varied to have thesame or different cross-sectional areas (i.e., varying thicknesses). Theextension 66 and compressing portion 64 are, in this embodiment,different in cross-sectional areas. Here, the cross-sectional area ofmost of the extension 66 is narrower than the lowermost portion of theextension 66 and the cross-section of this lowermost portion of theextension 66 gradually increases in width until it is equal to thecross-section of the compressing portion 64, which is substantiallywider.

The extension 66 can be any shape or material so long as it delivers thepre-set compressive force to the tissue at the compressing portion 64and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 63is a relatively sinusoidal curve traversing more than one sinusoidalperiod. Again, only for illustrative purposes, the cross-section of theOTC device 63 has a racetrack shape, but can be changed as desired toother shapes (e.g., circular, ovular, polygonal, etc.). As describedabove, variation of any attribute of the OTC device 63 allows foradjustment of the compressive and reactive force constants thereof onthe compressed tissue in the central region 67.

FIG. 7 illustrates a sixth exemplary embodiment of the OTC staple 70according to the invention. This variation has some of the features ofthe above embodiments. In this variant, like the embodiment of FIG. 3,the OTC portion is symmetrical with respect to the bridge 71 and thelegs 72 and the OTC device 73 is a separate part from the bridge 71 andlegs 72 of the staple 70. Like the embodiment of FIGS. 4 to 6, thecompressing portion 74 has a width greater than the separation distanceof the two legs 72 and has ports 75 with a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thelegs 72, but slightly larger. The legs 72 pass through these ports 75.In this configuration, movement of the OTC device 73 out of thebridge-legs plane is substantially prevented. The extension 76 of theOTC device 73 traverses from the bridge 71 to the compressing portion74. Because the ports 75 are shaped to be slightly larger than thecross-section of the legs 72, the extension 76 acts as a compressionspring in the bridge-legs plane as the compressing portion 74 moves upand down along the upper portion of the legs 72. It is the extension 76that provides the load-bearing force when tissue is compressed withinthe central region 77 of the staple 70. Because of the form-locking andsliding connection between the compressing portion 74 and the legs 72,the OTC device 73 of the sixth embodiment behaves similar to the OTCdevices of FIGS. 4 to 6.

Connection of the OTC device 73 to the staple 70, for example, at thebridge 71, can occur by any fastening measure. One exemplary connectionmethod is spot welding, which is indicated in FIG. 7 by referencenumeral 78. The type or types of material of the staple portions 71, 72and the OTC device 73 will direct a preferable attachment method. In thecase of attaching two materials together that are not suited to bewelded, soldered or brazed, other attachment methods can be used such ascrimping and adhesive bonding. Features can be added to one or both ofthe two components to facilitate the crimp or bond. These features couldbe configured to have the components snap together. In the case ofdissimilar materials, for example, if the staple material is stainlesssteel and the OTC device 73 is of nickel titanium alloy, then preferredattachment measures include crimping, adhesive bonding, or snapping.

It is noted that the extensions (i.e., springs) in each of FIGS. 2, 3,5, and 6 are in the same plane, which can be the bridge-legs plane (asshown) or out of that plane. In comparison to these embodiments, theextension 76 has the springs residing in different planes (i.e., onenext to the other.

Like the previous embodiments, the OTC device 73 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portions of theextension 76 or the compressing portion 74 can be varied to have thesame or varying cross-sectional areas (i.e., varying thicknesses). Theextension 76 and the compressing portion 74 are, in this embodiment,different in cross-sectional areas. Here, the cross-sectional area ofmost of the extension 76 is narrower than the lowermost portion of theextension 76 and the cross-section of this lowermost portion of theextension 76 gradually increases in width until it is equal to thecross-section of the compressing portion 74, which is substantiallywider.

The extension 76 can be any shape or material so long as it delivers thepre-set compressive force to the tissue at the compressing portion 74and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 73is a relatively sinusoidal curve traversing more than one sinusoidalperiod. Again, only for illustrative purposes, the cross-section of theOTC device 73 has a racetrack shape, but can be changed as desired toother shapes (e.g., circular, ovular, polygonal, etc.). As describedabove, variation of any attribute of the OTC device 73 allows foradjustment of the compressive and reactive force constants thereof onthe compressed tissue in the central region 77.

FIG. 8 illustrates a seventh exemplary embodiment of the OTC staple 80according to the invention. This variation has some of the features ofthe above embodiments. In this variant, like the embodiment of FIG. 3,the OTC portion is symmetrical with respect to the bridge 81 and thelegs 82, and the OTC device 83 is a separate part from the bridge 81 andlegs 82 of the staple 80. Like the embodiment of FIGS. 4 to 7, thecompressing portion 84 has a width greater than the separation distanceof the two legs 82 and has ports 85 with a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thelegs 82, but slightly larger. The legs 82 pass through these ports 85.In this configuration, movement of the OTC device 83 out of thebridge-legs plane is substantially prevented. The extension 86 of theOTC device 83 traverses from the bridge 81 to the compressing portion84. Because the ports 85 are shaped to be slightly larger than thecross-section of the legs 82, the extension 86 acts as a compressionspring in the bridge-legs plane as the compressing portion 84 moves upand down along the upper portion of the legs 82. It is the extension 86that provides the load-bearing force when tissue is compressed withinthe central region 87 of the staple 80. Because of the form-locking andsliding connection between the compressing portion 84 and the legs 82,the OTC device 83 of the seventh embodiment behaves similar to the OTCdevices of FIGS. 4 to 7.

Like the previous embodiments, the OTC device 83 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portions of theextension 86 or the compressing portion 84 can be varied to have thesame or varying cross-sectional areas (i.e., varying thicknesses). Theextension 86 and the compressing portion 84 are, in this embodiment,different in cross-sectional areas. Here, the cross-sectional area ofmost of the extension 86 is smaller and narrower than the lowermostportion of the extension 86 and the cross-section of this lowermostportion gradually increases in width until it is equal to thecross-section of the compressing portion 84, which is substantiallywider. Also, the cross-sectional area of this extension 86 is smallerthan previous embodiments (but it need not be).

The extension 86 can be any shape or material so long as it delivers thepre-set compressive force to the tissue at the compressing portion 84and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 83is a relatively sinusoidal curve traversing a more than two periods andalso having a second “interior” curve that traverses sinusoidal periods.In this embodiment, the OTC device 83 has an uppermost portion that is,in contrast to the embodiments of FIGS. 3, 6, and 7 a single barextending along a majority of the bridge 81.

Connection of the OTC device 83 to the staple 80, for example, at thebridge 81, can occur by any fastening measure. One exemplary connectionmethod is spot welding, which is indicated in FIG. 8 by referencenumeral 88. Because there is contact over most of the bridge 81, the OTCdevice 83 can be welded over the entire length thereof. The type ortypes of material of the staple portions 81, 82 and the OTC device 83will direct a preferable attachment method. In the case of attaching twomaterials together that are not suited to be welded, soldered or brazed,other attachment methods can be used such as crimping and adhesivebonding. Features can be added to one or both of the two components tofacilitate the crimp or bond. These features could be configured to havethe components snap together. In the case of dissimilar materials, forexample, if the staple material is stainless steel and the OTC device 83is of nickel titanium alloy, then preferred attachment measures includecrimping, adhesive bonding, or snapping.

Only for illustrative purposes, the cross-section of the OTC device 83has a racetrack shape, but can be changed as desired to other shapes(e.g., circular, ovular, polygonal, etc.). As described above, variationof any attribute of the OTC device 83 allows for adjustment of thecompressive and reactive force constants thereof on the compressedtissue in the central region 87.

FIG. 9 illustrates an eighth exemplary embodiment of the OTC staple 90according to the invention. This variation has some of the features ofthe above embodiments. In this variant, like the embodiment of FIG. 3,the OTC portion is symmetrical with respect to the bridge 91 and thelegs 92, and the OTC device 93 is a separate part from the bridge 91 andlegs 92 of the staple 90. Like the embodiment of FIGS. 4 to 8, thecompressing portion 94 has a width greater than the separation distanceof the two legs 92 and has ports 95 with a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thelegs 92, but slightly larger. The legs 92 pass through these ports 95.In this configuration, movement of the OTC device 93 out of thebridge-legs plane is substantially prevented. The extension 96 of theOTC device 93 traverses from the bridge 91 to the compressing portion94. Because the ports 95 are shaped to be slightly larger than thecross-section of the legs 92, the extension 96 acts as a compressionspring in the bridge-legs plane as the compressing portion 94 moves upand down along the upper portion of the legs 92. It is the extension 96that provides the load-bearing force when tissue is compressed withinthe central region 97 of the staple 90. Because of the form-locking andsliding connection between the compressing portion 94 and the legs 92,the OTC device 93 of the eighth embodiment behaves similar to the OTCdevices of FIGS. 4 to 8.

Like the previous embodiments, the OTC device 93 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portion(s) of theextension 96 or the compressing portion 94 can be varied to have thesame or varying cross-sectional areas (i.e., varying thicknesses). Theextension 96 and the compressing portion 94 are, in this embodiment,different in cross-sectional areas. Here, the cross-sectional area ofmost of the extension 96 is smaller and narrower than the lowermostportion of the extension 96 and the cross-section of this lowermostportion gradually increases in width until it is equal to thecross-section of the compressing portion 94, which is substantiallywider. Also, the cross-sectional area of this extension 96 is smallerthan previous embodiments (but need not be). With such a relativelysmaller cross-sectional shape, the curves of the extension 96 might tendto deform or move out of the bridge-legs plane, which tendency canincrease or decrease depending upon the material of the extension 96. Toprevent such deformation and/or movement, a plurality of guiding tabs 99are disposed at one or more of the outside ends of each periodic curveadjacent the legs 92. These guiding tabs 99 are shaped in a similarmanner to the ends of the compressing portion 94, in that they haveports with a cross-sectional shape substantially corresponding to thecross-sectional shape of the upper portion of the legs 92 but slightlylarger. The embodiment illustrated in FIG. 9 provides each guiding tab99 with two relatively parallel plates each having one of the two portsthrough which the respective leg 92 is disposed Like the lower portionof the extension 96, the cross-sectional area of the extension graduallyincreases in width until it is equal to the larger cross-section of theplate of the guiding tab 99. Another alternative of the guiding tab 99is to have only a single plate with a single port. In such an embodiment(assuming the material was the same as a dual-plate embodiment), thecurves of the extension 96 would be slightly stiffer because of theabsence of the exterior curve of the guiding tab 99.

The extension 96 can be any shape or material so long as it delivers thepre-set compressive force to the tissue at the compressing portion 94and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 93is a relatively sinusoidal curve having a second interior curve thattraverses a few sinusoidal periods and, in this embodiment, has anuppermost portion that is, like the embodiment of FIG. 8, a single barextending along a majority of the bridge 91. Connection of the OTCdevice 93 to the staple 90, for example, at the bridge 91, can occur byany fastening measure. One exemplary connection method is spot welding,which is indicated in FIG. 9 by reference numeral 98. Alternatively, theweld can be over the entire span contacting the bridge 91. The type ortypes of material of the staple portions 91, 92 and the OTC device 93will direct a preferable attachment method. In the case of attaching twomaterials together that are not suited to be welded, soldered or brazed,other attachment methods can be used such as crimping and adhesivebonding. Features can be added to one or both of the two components tofacilitate the crimp or bond. These features could be configured to havethe components snap together. In the case of dissimilar materials, forexample, if the staple material is stainless steel and the OTC device 93is of nickel titanium alloy, then preferred attachment measures includecrimping, adhesive bonding, or snapping.

Again, only for illustrative purposes, the cross-section of the OTCdevice 93 has a racetrack shape, but can be changed as desired to othershapes (e.g., circular, ovular, polygonal, etc.). As described above,variation of any attribute of the OTC device 93 allows for adjustment ofthe compressive and reactive force constants thereof on the compressedtissue in the central region 97.

FIG. 10 illustrates a ninth exemplary embodiment of the OTC staple 100according to the invention. This variation has some of the features ofthe above embodiments. In this variant, like the embodiment of FIG. 3,the OTC portion is symmetrical with respect to the bridge 101 and thelegs 102, and the OTC device 103 is a separate part from the bridge 101and legs 102 of the staple 100. The compressing portion 104, however, isunlike all of the previous embodiments. Here, the compressing portion104 is formed from two compressing plates, each of these plates beingattached to a respective lower end of two halves of the OTC device 103.The shape of the compressing portion 104 need not be a plate. It can becylindrical, for example. Like previous embodiments, the lowermost endof the extension 106 gradually increases in cross-section until it isequal to the compressing portion 104. Each compressing plate, then,extends towards a respective one of the legs 102 and defines arespective port 105 for receiving therein the leg 102. The port 105 hasa shape substantially corresponding to the cross-sectional shape of theupper portion of the legs 102, but is slightly larger. The legs 102 passthrough each port 105 to form the OTC device 103. In this configuration,movement of the OTC device 103 out of the bridge-legs plane issubstantially prevented. The extension 106 of the OTC device 103traverses from the bridge 101 to the plates of the compressing portion104. Because the ports 105 are shaped to be slightly larger than thecross-section of the legs 102, the extension 106 acts as a compressionspring in the bridge-legs plane as the compressing portion 104 moves upand down along the upper portion of the legs 102. It is the extension106 that provides the load-bearing force when tissue is compressedwithin the central region 107 of the staple 100.

In this embodiment, as compared to previous OTC device embodiments, thetwo sides of the OTC device 103 move independent from one another. Thus,if tissue varies in any characteristic within the central portion 107(e.g., hardness, thickness, density), the optimal tissue compressionforce can be delivered independently and differently for each of the twodiffering tissue segments contacting the respective one of the sides ofthe OTC device 103.

Connection of the OTC device 103 to the staple 100, for example, at thebridge 101, can occur by any fastening measure. One exemplary connectionmethod is spot welding, which is indicated in FIG. 10 by referencenumeral 108. As the upper portion contacts almost all of the bridge 101,the weld 108, instead, can span any amount of the bridge 101. The typeor types of material of the staple portions 101, 102 and the OTC device103 will direct a preferable attachment method. In the case of attachingtwo materials together that are not suited to be welded, soldered orbrazed, other attachment methods can be used such as crimping andadhesive bonding. Features can be added to one or both of the twocomponents to facilitate the crimp or bond. These features could beconfigured to have the components snap together. In the case ofdissimilar materials, for example, if the staple material is stainlesssteel and the OTC device 103 is of nickel titanium alloy, then preferredattachment measures include crimping, adhesive bonding, or snapping.

Like the previous embodiments, the OTC device 103 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portions of theextension 106 or the compressing portion 104 can be varied to have thesame or varying cross-sectional areas (i.e., varying thicknesses). Theextension 106 and the plates of the compressing portion 104 are, in thisembodiment, different in cross-sectional areas. Here, thecross-sectional area of most of the extension 106 is smaller andnarrower than the lowermost portion of the extension 86 and thecross-section of this lowermost portion gradually increases in widthuntil it is equal to the cross-section of the respective plate of thecompressing portion 104, which is substantially wider.

The extension 106 can be any shape or material so long as it deliversthe pre-set compressive force to the tissue at the compressing portion104 and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 103is a relatively sinusoidal curve having almost two sinusoidal periodsand, in this embodiment, has an uppermost portion that is (like theembodiments of FIGS. 8 and 9) a single bar extending along a majority ofthe bridge 101. For illustrative purposes, the cross-section of the OTCdevice 103 has an ovular shape, but can be changed as desired to othershapes (e.g., circular, racetrack, polygonal, etc.). As described above,variation of any attribute of the OTC device 103 allows for adjustmentof the compressive and reactive force constants thereof on thecompressed tissue in the central region 107.

FIGS. 11 and 11A illustrate a tenth exemplary embodiment of the OTCstaple 110 according to the invention. This variation has some of thefeatures of the above embodiments. In this variant, like the embodimentof FIG. 3, the OTC portion is symmetrical with respect to the bridge 111and the legs 112, and the OTC device 113 is a separate part from thebridge 111 and legs 112 of the staple 110. The compressing portion 114is like the embodiment of FIG. 10—it is formed from two compressingplates, each of these plates being attached to a respective lower end oftwo halves of the OTC device 113. The lowermost end of the extension 116gradually increases in cross-section until it is equal in area to thecompressing portion 114. Each compressing plate, then, extends towards arespective one of the legs 112 and defines a respective port 115 forreceiving therein one of the legs 112. In FIG. 11, the ports 115 cannotbe seen because of the presence of one-way washers 119 (describedbelow), but the port 115 is visible in FIG. 11A.

As set forth above, each port 115 has a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thelegs 112 but is slightly larger. The legs 112 pass through each port 115to form the OTC device 113. Because the ports 115 are shaped to beslightly larger than the cross-section of the legs 112, the extension116 acts as a compression spring in the bridge-legs plane as thecompressing portion 114 moves up and down along the upper portion of thelegs 112. In this configuration, movement of the OTC device 113 out ofthe bridge-legs plane is substantially prevented. It is the extension116 that provides the load-bearing force when tissue is compressedwithin the central region 117 of the staple 110. In this embodiment(like the embodiment of FIG. 10), the two sides of the OTC device 113move independent from one another. Thus, if tissue varies in anycharacteristic within the central portion 117 (e.g., hardness,thickness, density), the optimal tissue compression force can bedelivered independently and differently for each of the two differingtissue segments contacting the two plates of the compressing portion114.

Introduced for the first time in this embodiment are one-way devices 119(one exemplary embodiment being a star washer that is illustrated inFIGS. 11 and 11A) disposed on the leg 112 between the bridge 111 and thecompressing portion 114. These devices 119 are shaped to freely move onthe leg 112 upwards towards the bridge 111 but not to move in theopposite direction. Thus, as tissue is being compressed within thecentral region 117 as the distal ends of the legs 112 are curved in thestapling action, the tissue presses against the compressing portion 114and moves the compressing portion 114 up towards the bridge 111. Oncethe stapling force is removed from the staple 110 (after stapling iscomplete), the tissue will most likely not press the washers 119 anyfurther without any additionally supplied outside force. Thus, thewashers 119 limit further movement of the compressing portion 114 fromthe then-current location of the washers 119 towards the first bend ofthe legs 112. These washers also add some friction when the firststapling movement occurs, which friction may be used to add to and makeup the compression coefficients of the OTC device 113. If the stapledtissue swells, it is possible for the washers 119 to be moved if theforce is sufficient. After such swelling ends and desiccation of thetissue occurs, the compressing portions 114 will be limited in furthercompression by these washers 119.

Like the previous embodiments, the OTC device 113 can be shaped withvariations in cross-section and other spatial characteristics and can beformed with a variety of material compositions. Any portions of theextension 116 or the compressing portion 114 can be varied to have thesame or varying cross-sectional areas (i.e., varying thicknesses). Theextension 116 and the plates of the compressing portion 114 are, in thisembodiment, different in cross-sectional areas. Here, thecross-sectional area of most of the extension 116 is smaller andnarrower than the lowermost portion of the extension 116 and thecross-section of this lowermost portion gradually increases in widthuntil it is equal to the cross-section of the respective plate of thecompressing portion 114, which is substantially wider.

The extension 116 can be any shape or material so long as it deliversthe pre-set compressive force to the tissue at the compressing portion114 and as long as it allows for absorption of forces greater than thispre-set force. An exemplary embodiment selected for this OTC device 113is a relatively sinusoidal curve traversing more than two sinusoidalperiods and having a second “interior” curve. In this embodiment, theOTC device 113 has an uppermost portion that is (like the embodiments ofFIGS. 8 to 10) a single bar extending along a majority of the bridge111. Connection of the OTC device 113 to the staple 110, for example, atthe bridge 111, can occur by any fastening measure. One exemplaryconnection method is spot welding, which is indicated in FIG. 11 byreference numeral 118. This process can be changed if desired. The typeor types of material of the staple portions 111, 112 and the OTC device113 will direct a preferable attachment method. In the case of attachingtwo materials together that are not suited to be welded, soldered orbrazed, other attachment methods can be used such as crimping andadhesive bonding. Features can be added to one or both of the twocomponents to facilitate the crimp or bond. These features could beconfigured to have the components snap together. In the case ofdissimilar materials, for example, if the staple material is stainlesssteel and the OTC device 113 is of nickel titanium alloy, then preferredattachment measures include crimping, adhesive bonding, or snapping.

For illustrative purposes, the cross-section of the OTC device 113 has aracetrack shape, but can be changed as desired to other shapes (e.g.,circular, ovular, polygonal, etc.). As described above, variation of anyattribute of the OTC device 113 allows for adjustment of the compressiveand reactive force constants thereof on the compressed tissue in thecentral region 117.

FIG. 12 illustrates an eleventh exemplary embodiment of the OTC staple120 according to the invention. This variation is significantlydifferent from the above embodiments. The OTC device 123 is, as above, aseparate part from the bridge 121 and legs 122 of the staple 120. Here,however, the compressing portion 124 is a C-beam having ports 125 thatpermit passage of a respective one of the legs 122 therethrough. Eachport 125 has a shape substantially corresponding to the cross-sectionalshape of the upper portion of the legs 122 but is slightly larger. Thelegs 122 pass through each port 125 to form the OTC device 123. In thisconfiguration, movement of the OTC device 123 out of the bridge-legsplane is substantially prevented.

The C-beam shape is useful for a variety of reasons. First, the C-shapeprovides a central cavity in which a distal end of a compression device126 can be held or fastened. Next, the C-shape also increases resistanceto bending forces as compared to a simple rectangular plate, as is knownin construction. Finally, orienting the open portion of the “C” awayfrom the tissue presents a flat compressing plate to the tissue to becompressed. With such a shape, the tissue can be compressed evenly, withno singular pressure points. Of course, the C-shape is not the onlypossible cross-sectional shape. The compressing portion 124 can be arectangular plate, an I-beam, an L-beam, or any other desired shape.

The compression device 126 can take any form (see, e.g., FIG. 13). Theexemplary embodiment of FIG. 12 illustrates the compression device 126as a conically expanding compression spring. Connection of the spring126 and compressing portion 124 to the staple 120, for example, at thebridge 121, can occur by any fastening measure. The illustratedexemplary proximal connection method is a ring of the spring materialwrapping around the bridge 121. This proximal end is secured at thecenter of the bridge 121 and held in place there by placingprotuberances 128 on the bridge 121. These protuberances prevent lateralmovement of the proximal ring towards either of the two legs 122. Ofcourse, this ring can be welded or fastened to the bridge 121 by anyfastening process. The distal end of the spring is a relatively circularcoil lying in the same plane as the interior cavity of the C-beam andhaving an outer diameter just slightly less than the interior diameterof the C-shaped cavity of the compressing portion 124. Thus, the ends ofthe C-shape can be used to retain the distal end of the spring 126within the cavity. Of course, other fastening measures can be used tosecure the spring distal ends to the compressing portion 124.

It is the spring 126 that provides the load-bearing force when tissue iscompressed within the central region 127 of the staple 120. Like theprevious embodiments, the OTC device 123 can be shaped with variationsin cross-section, winding, and other spatial characteristics and can beformed with a variety of material compositions. Any portions of thespring 126 or the compressing portion 124 can be varied. In particular,the spring 126 can be any shape or material so long as it delivers thepre-set compressive force to the tissue through the compressing portion124 and as long as it allows for absorption of forces greater than thispre-set force. As described above, variation of any attribute of the OTCdevice 123 allows for adjustment of the compressive and reactive forceconstants thereof on the compressed tissue in the central region 127.

FIG. 13 illustrates a twelfth exemplary embodiment of the OTC staple 130according to the invention. This variation is similar to the embodimentof FIG. 12. The OTC device 133 is, as above, a separate part from thebridge 131 and legs 132 of the staple 130 and the compressing portion134 is a C-beam having ports 135 that permit passage of a respective oneof the legs 132 therethrough. Each port 135 has a shape substantiallycorresponding to the cross-sectional shape of the upper portion of thelegs 132 but is slightly larger. The legs 132 pass through each port 135to form the OTC device 133. In this configuration, movement of the OTCdevice 133 out of the bridge-legs plane is substantially prevented.

The C-beam shape has the same benefits as described in the eleventhembodiment of FIG. 12. Like that embodiment, the C-shape is notrequired; the compressing portion 134 can be a rectangular plate, anI-beam, an L-beam, or any other desired shape.

The compression device 136 can take any form. In the exemplaryembodiment of FIG. 13, the compression device 136 is a pair ofcompression springs 136. Connection of these springs 136 and thecompressing portion 134 to the staple 130, for example, at the bridge131, can occur by any fastening measure. The illustrated exemplaryproximal connection method is a narrowing of the spring diameter to beequal or less than the diameter of the legs 132 at the connection pointto the bridge 131. Thus, the springs 136 can be held by the forceimparted on the legs 132 by press-fitting the narrower spring rings ontoa desired location on the legs 132. Alternatively and/or additionally,the almost ninety degree bend at the legs-bridge intersection forms astop preventing further upward movement of the distal ends of eachspring 136. Of course, the upper ring(s) can be fastened to the staple130 by any measure, such as welding, crimping, etc.

Like the embodiment of FIG. 12, the distal end of the springs 136 inFIG. 13 is formed by a relatively circular coil lying in the same planeas the interior cavity of the C-beam and having an outer diameter justslightly less than the interior diameter of the C-shaped cavity of thecompressing portion 134. Thus, the ends of the C-shape can be used toretain the distal end of the spring 136 within the cavity. The coils canbe welded to the C-beam, for example. Of course, other fasteningmeasures and coil configurations can be used to secure the distal endsof the springs 136 to the compressing portion 134.

It is the springs 136 that provide the load-bearing force when tissue iscompressed within the central region 137 of the staple 130. Like theprevious embodiments, the OTC device 133 can be shaped with variationsin cross-section and other spatial characteristics and can be formedwith a variety of material compositions. Any portions of the springs 136or the compressing portion 134 can be varied. In particular, the spring136 can be any shape or material so long as it delivers the pre-setcompressive force to the tissue through the compressing portion 134 andas long as it allows for absorption of forces greater than this pre-setforce. As described above, variation of any attribute of the OTC device133 allows for adjustment of the compressive and reactive forceconstants thereof on the compressed tissue in the central region 137.

The spring 136 shown in FIG. 12 floats between the legs 132 and does nottouch either leg 132. In contrast, the springs 135 of FIG. 13 wraparound the legs throughout the entire length. This orientation presentsthe possibility of resistance (i.e., friction) imparted upon the springs136 by the legs 132 when the springs 136 are compressed. This resistancemay be desirable depending upon the desired OTC device compressioncoefficient. If resistance is to be reduced, then sleeves 138 can beinserted onto the legs 132 such that they “lubricate” or reduceresistance of spring compression. These sleeves 138 can be made ofpolytetrafluoroethylene (PTFE), for example.

FIG. 14 illustrates a thirteenth exemplary embodiment of the OTC staple140 according to the invention. This variation is similar to theembodiments of FIGS. 12 and 13. The OTC device 143 is, as above, aseparate part from the bridge 141 and legs 142 of the staple 140 and thecompressing portion 144 is a C-beam having non-illustrated ports thatpermit passage of a respective one of the legs 142 therethrough (in theview of FIG. 14, the ports are blocked from view by the C-beam). Eachport has a shape substantially corresponding to the cross-sectionalshape of the upper portion of the legs 142 but is slightly larger. Thelegs 142 pass through each port to form the OTC device 143. In thisconfiguration, movement of the OTC device 143 out of the bridge-legsplane is substantially prevented.

The C-beam shape has the same benefits as described in the eleventhembodiment of FIG. 12. Like that embodiment, the C-shape is notrequired; the compressing portion 144 can be a rectangular plate, anI-beam, an L-beam, or any other desired shape.

The compression device 146 can take any form. The exemplary embodimentof FIG. 14 is a pair of compression springs 146. Like the single spring136 shown in FIG. 12, the compression springs 146 of this embodimentfloat between the legs 142 and do not touch either leg 142. Connectionof these springs 146 to the staple 140, for example, at the bridge 141,can occur by any fastening measure. The illustrated exemplary proximalconnection method is a second C-beam disposed against the bridge 141 andconnected thereto by any fastening measure, such as spot welds 148, forexample. With such a connection configuration, each of the springs 146can be formed with a relatively circular coil lying in the same plane asthe interior cavity of each C-beam and having an outer diameter justslightly less than the interior diameter of the respective C-shapedcavity of the compressing portion 144. Thus, the ends of the C-shape canbe used to retain the distal end of the spring 146 within the cavity.These end coils can be press-fit or slid into the C-beam cavity forconnection thereto. Alternatively and/or additionally, these lower andupper loops can be fastened to the beams by welding, crimping, etc. Therespective interior cavities of the two C-beams can be of different orof equal size.

It is the springs 146 that provide the load-bearing force when tissue iscompressed within the central region 147 of the staple 140. Like theprevious embodiments, the OTC device 143 can be shaped with variationsin cross-section, winding, and other spatial characteristics and can beformed with a variety of material compositions. Any portions of thesprings 146 or the compressing portion 144 can be varied. In particular,the spring 146 can be any shape or winding or of any material so long asit delivers the pre-set compressive force to the tissue through thecompressing portion 144 and as long as it allows for absorption offorces greater than this pre-set force. As described above, variation ofany attribute of the OTC device 143 allows for adjustment of thecompressive and reactive force constants thereof on the compressedtissue in the central region 147.

FIG. 15 illustrates a fourteenth exemplary embodiment of the OTC staple150 according to the invention. The OTC device 153 is, as above, aseparate part from the bridge 151 and legs 152 of the staple 150. Here,however, this variation differs from the previous embodiments becausethe OTC device 153 is a cushion made of a compressible material.Examples of such material include, but are not limited to, closed cellpolyethylene foam, expanded polytetrafluoroethylene (PTFE), siliconerubber, silicone rubber foam, urethane, and electro-spun thermoplasticelastomers. This cushion 153 defines two channels 154 for receivingtherethrough a respective one of the legs 152. Because the staple legs152 taper inwards slightly in a direction from the intermediate portion155 of the staple 150 to the ends of the bridge 151 (although this taperis not a requirement), the cross-sectional area of the channels 154 arelarger than the cross-section of a portion of the legs 152 disposedinside the channels 154. By passing the legs 152 through each channel154, the OTC device 153 is formed.

It is this pillow 153 that provides the load-bearing force when tissueis compressed within the central region 157 of the staple 150. Like theprevious embodiments, the OTC device 153 can be shaped with variationsin cross-section and other spatial characteristics and can be formedwith a variety of material compositions. The exemplary embodimentillustrated in FIG. 15 is a pillow having a racetrack cross-sectionalshape in the transverse direction. However, the pillow can be circular,ovular, rectangular, and polygonal in its outer transverse shape.

Any portion of the pillow 153 can be varied so long as it delivers thepre-set compressive force to the tissue at the distal end of the pillow153 and as long as it allows for absorption of forces greater than thispre-set force. As described above, variation of any attribute of the OTCdevice 153 allows for adjustment of the compressive and reactive forceconstants thereof on the compressed tissue in the central region 157.

FIG. 16 illustrates a fifteenth exemplary embodiment of the OTC staple160 according to the invention. This variation is different from theprevious embodiments. The OTC device 163 is, as above, a separate partfrom the bridge 161 and legs 162 of the staple 160. The OTC device is aplate 163 made of a semi-compressible material having properties thatwill be described in detail below. Examples of such a material include,but are not limited to, polyurethane and silicone rubber. The plate 163defines two channels 164 for receiving therethrough a respective one ofthe legs 162. Because the legs 162 taper inwards slightly in thebridge-legs plane in a direction from the intermediate portion 165 ofthe staple 160 to the ends of the bridge 161 (although this taper is nota requirement), the cross-sectional area of each of the channels 164 inthe bridge-legs plane is larger than the cross-section of the legs 162that are to be disposed inside the channels 164. This larger area isdefined by a hole that is longer in the bridge-legs plane than in theplane orthogonal thereto along the axis of the leg 162. In the exemplaryembodiment shown in FIG. 16, the cross-sectional shape of the channels164 are ovular or racetrack shaped. By passing the legs 162 through eachchannel 164, the OTC device 163 is formed.

It is noted that the staple 160 shown in FIG. 16 is different from theprior art staple of FIG. 1. Specifically, the connecting portion 166 ofthe legs 162 tapers in width outwardly in the direction beginning fromthe intermediate portion towards the bridge 161 in a plane that isorthogonal to the bridge-legs plane. Because the channels 164 have afixed width in the plane of the widening (which plane is orthogonal tothe bridge-legs plane), and due to the fact that the fixed width isclose in size to the lower-most portion of the connecting portion 166(nearest to the intermediate portion 165), the plate 163 will not beable to move upwards towards the bridge 161 unless the material of theplate 163 is semi-compressible. Knowledge about the material's abilityto compress and the resistance it provides to upward movement as theplate 163 progresses upward along the outwards taper of the leg wideningcan be used to set or adjust the compressive and reactive forceconstants thereof on the compressed tissue in the central region 167.Any portion of the plate 163 and of the upper leg taper can be varied solong as the OTC system (plate 163 and taper of the legs 162) deliversthe pre-set compressive force to the tissue at the distal end of theplate 163 and as long as it allows for absorption of forces greater thanthis pre-set force.

The OTC device of this embodiment can be shaped with variations incross-section, taper, and other spatial characteristics and can beformed with a variety of material compositions. The exemplary embodimentillustrated in FIG. 16 is a plate 163 having a racetrack cross-sectionalshape in the transverse direction. However, the pillow can be circular,ovular, rectangular, and polygonal in its outer transverse shape, forexample.

The OTC staple according to the invention is applied in the same manneras a conventional staple, that is:

-   -   the staple is loaded into a staple cartridge;    -   material to be stapled with the staple is placed between the        staple cartridge and an anvil; and    -   the anvil and staple are brought together to press the lower        portion of the legs against the anvil and bend the lower        portions inward to capture the material in the central region        and compress it between the bent portions and the compressing        portion of the staple.

Because the material to be stapled has a length less than the distancebetween the bent lower portions and the bridge, the captured materialpartially compresses the OTC device inside the staple to, thereby,effect the optimal tissue compression feature. When the staple andmaterial are released from the staple cartridge and anvil, the OTCdevice is imparting a pre-set compressive force against the compressedmaterial. Significantly, the OTC device is able to move while thematerial is going through its compression and expansion cycle(s) untilit finally reaches a steady state size. Even after reaching the steadystate, the OTC device imparts the desired compressive force (within anacceptable minimum range) so that the material is not permanentlydamaged due to overcompression.

For example, if the material is human tissue, when tissue is stapled,liquid is forced out of the tissue. During the desiccation period, thetissue compresses further and further. The OTC device compensates byenlarging to follow the tissue compression. At some point in time, thetissue begins to swell (due to the puncturing and compressing forcesimparted thereon). During the swelling period, the OTC devicecompensates by reducing to follow the tissue swelling.

The foregoing description and accompanying drawings illustrate theprinciples, preferred embodiments and modes of operation of theinvention. However, the invention should not be construed as beinglimited to the particular embodiments discussed above. Additionalvariations of the embodiments discussed above will be appreciated bythose skilled in the art.

Therefore, the above-described embodiments should be regarded asillustrative rather than restrictive. Accordingly, it should beappreciated that variations to those embodiments can be made by thoseskilled in the art without departing from the scope of the invention asdefined by the following claims.

1. A compression-self-adjusting staple, comprising: a substantiallyU-shaped staple having: a bridge; legs; and: an internally disposedcompression device having a bias portion with: a compression surfacemovably disposed between the legs; and a compression resistor: connectedto the bridge and to the compression surface; and being formed to resistmovement of the compression surface towards the bridge with a force. 2.The staple according to claim 1, wherein: the bridge is substantiallyrod-shaped with ends; and each of the legs has a base end integral witha respective one of the ends.
 3. The staple according to claim 1,wherein: the bridge and the legs define a bridge-leg plane; and the legsextend from the bridge at an angle of between 80 and 100 degrees in thebridge-leg plane.
 4. The staple according to claim 1, wherein: thecompression surface defines two orifices; and each of the legs extendsthrough one of the two orifices.
 5. The staple according to claim 1,wherein: the compression resistor defines at least one orifice pair; thecompression surface defines two orifices; and each of the legs extendsthrough one of the two orifices and one of the at least one orificepair.
 6. The staple according to claim 1, wherein: the compressionresistor defines a plurality of orifice pairs; the compression surfacedefines two orifices; and each of the legs extends through one of thetwo orifices and one of each of the orifice pairs.
 7. The stapleaccording to claim 1, wherein: the bridge and the legs define acompression axis; and the compression surface is movably disposedbetween the legs along the compression axis.
 8. The staple according toclaim 1, wherein the compression device is connected to the bridge. 9.The staple according to claim 8, wherein the compression resistorconnects the bridge to the compression surface.
 10. The staple accordingto claim 8, wherein the bridge, the legs, the compression resistor, andthe compression surface are integral.
 11. The staple according to claim1, wherein the compression resistor is at least partly disposed betweenthe legs.
 12. The staple according to claim 1, wherein the compressionresistor is disposed between the bridge and the compression surface. 13.The staple according to claim 1, wherein the force comprises apre-defined opposing force.
 14. The staple according to claim 1, whereinthe force comprises a substantially constant force.
 15. The stapleaccording to claim 1, wherein the force comprises a linearly increasingforce.
 16. The staple according to claim 1, wherein the compressionresistor has an anti-compressive spring constant imparting asubstantially constant anti-compressive force over a pre-definedcompression range.
 17. The staple according to claim 1, wherein thestaple and the compression device are of a biocompatible material. 18.The staple according to claim 1, wherein: the compression surface andthe legs define a central compression region in which is to be disposeda material to be compressed between the compression surface and staplingpoints when distal ends of the legs are deformed; and when the distalends are deformed in a staple closing direction into the centralcompression region, the bias portion resists movement of the compressionsurface in the staple closing direction with a pre-defined,substantially constant force.
 19. The staple according to claim 1,wherein the compression surface and the bias portion are shaped toimpart a pre-defined, substantially constant bias force upon materialdisposed between the compression surface and stapling points when thestapling points are deformed.
 20. The staple according to claim 1,wherein: when stapling points are deformed toward one another, materialdisposed between the compression surface and the stapling points iscompressed between the stapling points and the compression surface; andthe compression resistor maintains a substantially constant compressiveforce on the material within a pre-defined range independent of a degreeof compression between the stapling points and the compression surface.